The expanding universe is source of the thermodynamic arrow [1]}.
In a closed box all intermediate histories will eventually reach a
final state. However, the hugely extended final state of our cosmos
and significant effectively interaction less regions make it plausible
that all of today’s macroscopic decisions can be encoded there. So
the expansion is also source of the effective time arrow considered
here. Of course this is just a conjecture. Many aspects of cosmology
are not well known and it is not clear that in the limit of a large
final time the final state grows faster then needed for the decision
tree.
